Math

1. An encoder can type n words in t hour. The formula that relates n to t is . What kind of variation is it?

•  Inverse

• Direct

• Joint

• Combined

1. Which is an example of a direct linear variation?

• xy = 5

• y = 3/x

• y = 2x

• 3/y = x

1. Derive the equation for the variation using the table.

• y = 3x

• y = -3/x

• y = -3x

• xy = 3

1. If p varies directly as q and inversely as r, then which of the following equations describes the relation among the variables?

• p = kq/r

• 1/p = kr/q

• p = kr/q

• p = k/qr

Translate into equation, “y is directly proportional to x and inversely proportional to z”. Use k as constant of proportionality.

• y = kxz

• y = kz/y

• y = kx/z

• y = x/ky

What happens to T when h is tripled in the equation T=k/h?

• T is tripled

• T is multiplied by 6

• T is divided by 6

• T is divided by 3

7. If p varies directly as q, and p = 25 when q = 20 find q when p = 140.

• 4/5

• 500

• 112

• 70

8. If y varies inversely as x, and x = 10, y = 48. Find y when x = 32.

• 12

• 15

• 10

• 17

9. If c varies inversely as d, and c = 30, d = 9. Find d when c = 540.

• 1/2

• 2

• 1/3

• 3

If w varies directly as the square of x and inversely as y and z. if w =12 when x = 4, y = 2 and z = 20. Find w when x = 3, y = 8 and z = 5.

• 10

• 9

• 27/4

• 5